In order to increase the density of semiconductor devices, a plurality of semiconductor chips are stacked one over another. Such a semiconductor device is sometimes known as an MCP (Multi Chip Package).
The structure of MCP-type semiconductor devices is normally one in which an upper-level semiconductor chip is cross-stacked relative to a lower-level semiconductor chip to allow for wire bonding.
For example, patent literature article 1 discloses an MCP semiconductor device in which a rectangular second semiconductor chip (upper-level semiconductor chip) is stacked on a rectangular first semiconductor chip (lower-level semiconductor chip) installed on a wiring substrate, in a state in which the second semiconductor chip is rotated through 90° relative to the first semiconductor chip (patent literature article 1).